Spiral stitching device for sewing machines



Oct. 11, 1960 5.41. TOBIAS ET AL SPIRAL STITCHING DEVICE FOR SEWING MACHINES Filed Jan. 22, 1957 2 Sh eets-Sheet 1 NV 9 .L 5 0m Oct. 11, 1960 5. J. "roams ETAL SPIRAL STITCHING DEVICE FOR sswmc MACHINES Filed Jan. 22, 1957 2 Sheets-Sheet 2 IN V EN T0 STEPHEN J. TOBIAS WILLIAM KAUFMAN ATTORNEY Led tates Stephen J. Tobias, 17 Monroe Place, and William Kauf man, 575 King St., both of Port Chester, N.Y.

' Filed Jan. 22, 1957, Ser. No. 635,215

Claims. (Cl. 112-2 This invention relates to sewing'machines and more particularly to a part thereof for producing a spiral seam on a work piece. More particularly, the present invention is directed to a mechanism for producing a spiral stitch on brassiere cups as well as on other shaped forms and fiat work pieces.

It is an object of this invention to provide a mechanism which may be an attachment built into the machine and in a custom manner. The present invention may also be an attachment which may be easily and rapidly aflixed to existing conventional sewing machines. I

It is a further object of the present invention to provide a spiral stitching attachment for sewing machines which has a simple construction with relatively few parts, yet

is extremely effective for the purposes intended. V

A further object of the present invention is the provision of a novel spiral stitching attachment which may be rapidly returned to its starting position after the "completion of stitching on the work piece without necessitating any operation except the disengagement of the clutch. Heretofore, rapid production of brassiere elements was curtailed because many manual operations were necessary before the spiral stitching mechanism was returned to its initial starting position after the completion of stitching of a work piece. The present invention is designed to eliminate these manual manipulations and reduce the operation to its simplest arrangement.

Another object of the present invention is to provide a spiral stitching mechanism which has all elements with the exception of the movable feed plate mounted below the level of the table. a

A still further object of the present invention is the provision of means to enable the operator to pick-up a broken stitch precisely at the point of rupture and continue on to complete the stitching of the work piece.

The above and other features, objects and advantages of the present invention will'be fully understood from the following description considered in connection with the accompanying illustrative drawings. g

Fig. 1 is a top plan view of our spiral stitching device constructed in accordance with the present invention with the work table broken away for purposes of clarity,

Fig. 2 is a side elevational view thereof having parts thereof broken away for purposes of clarity. V,

Fig. 3 is a sectional view taken along the lines 3-3 of Fig. 2 and Fig. 4 is an alternate embodiment of ,the cylindrical cam.

Referring more particularly to the drawingsa sewing machine of the conventional design is shown having a head portion 12 and a reciprocating needle-holding mechanism 14 together with a suitable lateral work feeding means indicated diagrammatically by. the numeral 16. It should be understood that the sewing machine 10 being of well known construction, forms no part of the present invention. V

Our invention comprises a structure suitable ,for attachment to existing sewing machines or may form a 2355551 Patented Oct. 11, 1960 custom unit incorporating a sewing machine, a spiral stitching device, and all other necessary equipment The device comprises a conventional work table 18 on which a sewing machine 10 is mounted, however, there is a relatively long, narrow slit-like opening 20 in the table. Covering the slit-like opening 20 in the table is a flat feeder plate 22. This feeder plate 22 is adapted to move in the direction of the arrow A during stitching of the work piece and in the direction of the arrowB on return of the feeder plate 22 to its initial stitching position (Fig. 2). The mechanism for moving the plate 22 in a rectilinear fashion is located below the level of the table and may be hidden from view by means of a skirt (not shown). Thus, no dangerous, or dirty oil containing mechanisms are located above the level of the work table to injure the operator or soil the merchandise to be stitched. The stitching mechanism is mounted on two spaced plates 24 and 26. The latter are secured to the underside of the Work table 18 by any suitable securing means, such as screw 19.

Mounted on said spaced plates 24 and 26 is a cam of circular cross-section or a cylindrical cam 28 which is freely rotatable on shaft 30. Cam 28 is provided with a continuous'helical groove or track 32 which has a predetermined and changing pitch angle. The pitch angle is so chosen that a spiral stitching pattern is made on the brass-iere cup which consists of a series of concentric spirals being preferably equally spaced apart. Follower 34 continually engages the leading edge 33 of track 32. This is accomplished by means of a relatively flat spring 36 which is wound around the circumference of portion 38 of the cam 28 and has its free end 40 secured to plate 26. Thus, as the feeder plate 22 is moved to the right as seen in Fig. 2 the spring 36 is tensioned and consequently biases the leading edge 33 of track 32 toward the follower 34. The spring 36 connected at one end to the cam 28 and at the other end to plate 26 is tensioned when the cam 28 is rotated in a clockwise direction by the main drive shaft 42. When the cam 28 rotates, the

follower 34 is carried along since it iscaptured in the track 32 of the cam 28. The cam 28 is thus biased in a counterclockwise direction thereby forcing the leading edge 33. of the track 32 in continual engagement under spring pressure with the follower 34. It should be noted that the follower 34 is connected to the feeder plate 22 by'means of bridging element 42. Our spiral stitching device is driven from a main drive shaft 43 by any suitable motor means (not shown) and has worm 44 mounted thereon driving worm gear 45. Worm 46 mounted on the shaft of worm gear 45 drives another worm gear 47. In addition, spur gear 48 mounted on the shaft of worm gear 47 meshes with spur gear 50 mounted on shaft 30 adjacent to -cylindrical cam28. Aflixed to spur gear 50 is a spring-urged collar arrangement 52 between the shoulders of which is fitted one end of lever 54. Lever 54 is pivoted at 56 on support 58. The other end of lever 54 is engaged by the free end of push rod 60 which is in turn connected at 62 with the shaft 64. Shaft 64 is preferably terminated in a foot pedal 66 (Fig. 2). The right hand face 65 of spur gear 50 functions as a clutch plate. Likewise, the adjacent left hand end 67 of cylindrical cam 28 functions as the other clutch plate of the device. It should be noted that a magnetic clutch may be employed in place of the present mechanical clutch without departing from the spirit of the invention. a

The feeder plate 22 is provided with a projection 68 which is adapted to puncture the hemispherical-shaped brassiere cup at its polar axis. It should be apparent, therefore, that when the feeder plate 22 is moved rectilinearly by a suitable drive means the work is moved therewith. At the other end of feeder plate 22 is a manual control knob 70 by which the operator may move the feeder plate 22 after the completion of stitching of a brassiere element to the initial stitching position for stitching of another brassiere element. The operation of the device is as follows: The hemispherical-shaped brassiere cup C is inserted at its polar axis on the projection 68 of the plate 22. Clutch face 65 of spur gear 50 is engaged with clutch face 67 of the adjacent cylindrical cam 28. Thus, the main drive shaft 42 operated by a motor drives the cylindrical cam 28 through a speed reduction arrangement consisting of reduction gears 44, 45, 46, 47, 48 and 50. Consequently, the follower 34 biased against the leading edge 33 of the track 32 in cylindrical cam 28 commences to move along the helical path grooved in the cylindrical cam. The motion of the lateral work-feeding means 16 and the movement of the plate 22 in the direction of arrow A (Fig. 2) causes the brassiere cup to rotate, and at the same time the sewing machine stitches in a spiral pattern as the sewing machine moves from the polar axis in an outward direction. After the stitching of the brassiere cup is completed the cup is removed. The operator then steps on foot pedal 66 to thereby disengage clutch faces 65 and 67. This permits the feeder plate 22 to be easily and rapidly moved by means of a knob 70 in the direction of arrow B to the starting position of the feeder plate 22 since cylindrical cam 28 rotates freely on shaft '30. Upon the release of the foot pedal 66 the clutch faces 65 and 67 automically engage due to spring pressure. The main drive shaft 43 then commences to rotate the cylindrical cam 28 when another brassiere cup to be stitched is placed upon projection 68 of plate 22. If, for example, the thread being fed to the sewing machine breaks, then the clutch faces 65 and 67 may be disengaged and the follower brought back manually to the location where the stitching terminated. The clutch is engaged and 'due to the biasing action caused by fiat spring 36 there is no play in the mechanism and the stitch is picked up precisely at the point that it was terminated and the stitching of the cup completed.

Fig. 4 discloses another embodiment of a cylindrical cam 74 constructed in accordance with the present invention. The cam 74 is provided with a helical ridge 76 which is spirally wound around the cam 74. The helical ridge assumes a particular, predetermined pitch angle. Similarly to the cam 28 a fiat spring 36 may be wound around one end thereof to thereby bias the follower 34 against a side of helical ridge 76.

While we have shown and described the preferred embodiment of our invention, it will be understood that the latter may be embodied otherwise than as herein specifically illustrated or described and that in the illustrated embodiment certain changes in the details 'of construction and in the arrangement of parts may be made without departing from the underlying idea or principle of the invention within the scope of the appended claims.

What we claim is:

1. A spiral stitching device for a sewing machine including a stitch forming means and a mechanism for feeding work pieces later-ally relative to the central axis of said sewing machine, comprising a table support for said device having an elongated opening therein, a cam circular in cross-section and having a helical camming surface, means mounting said cam below the level of said table, a cam follower continually engaging said camming surface, a relatively flat feeder plate positioned above the level of said table, and in juxtaposition thereto, means for mounting a work piece on said feeder plate and having said stitch-forming means adapted to engage With said work piece, a bridging element located in said elongated opening and connecting said feeder plate to said cam follower, drive means for rotating said cam whereby said stitch-forming means produces a spiralling seam on said work .piece, a clutch for selectively connecting and disconnecting said drive means to said cam, operating means for said clutch whereby said drive means operatively moves said feeder plate in one direction and said clutch disengages said drive means by means of said operating means for said clutch at any selected position of said feeder plate to permit the latter to be moved manually in another direction, and a spring being substantially wound around a portion of said cam and having an end thereof secured to 'a part of said means mounting said cam, said spring biasing said follower into engagement 'with said camming surface.

2. A spiral stitching device for a sewing machine including a stitch forming means and a mechanism for feeding work pieces laterally relative to the central axis of said sewing machine, comprising a table support for said device having an elongated opening therein, a cam being circular in cross-section and having a helical camming surface, means mounting said cam below the level of said table, acam follower continually engaging said camming surface, a'relatively flat feeder plate positioned above the level of said table, means for mounting .a work piece on said feeder :platc' and having said stitch-forming means adapted to engage said -work piece, a bridging element located in said elongated opening and connecting said feeder plate to said cam follower, drive means for rotating said cam whereby said stitch-forming means produces a spiralling seam on said work piece, a clutch for selectively connecting and disconnecting said drive means, foot pedal means operatively connected to said clutch whereby said'drive means operatively moves .said feeder plate rectilinearly in one direction and said clutch disengages said drive means by means of said foot .pedal means at a selected position of said feeder plate to permit the latter to be moved manually in the opposite direction, and spring means being substantially wound around a portion of said .cam, said spring biasing said follower into continual engagement with said camming 'below .the level of said table, a cam follower continually engaging said camming surface, a relatively flat feeder plate positioned above the level of said table, means for mounting a work piece on said feeder plate and having said stitch-forming means adapted to engage said work piece, a bridging element located in said elongated opening and connecting said feeder plate to said cam follower, drive means for rotating said cam whereby said stitch-forming means produces a spiralling seam on said work piece, a clutch for selectively connecting and disconnecting said drive means, foot pedal means operatively connected to said-clutch whereby said drive means operatively moves said feeder .plate adjacent to the top surface of said table support in a direction toward said stitch-forming means, and said clutch disengages said drive means by means of said foot pedal means at a selected position of saidfeeder plate to permit the latter to be moved manually in the opposite direction and a fiat spring means substantially wound around an end of said cam, said spring biasing one wall of said grooved camming surface into continuous engagement with said follower.

4. Aspira'l stitching device for a sewing machine as set forth in claim 3 further comprising a knob mounted adjacent to one 'end'thereof, said means mounting said work piece on said feeder plate being an upstanding .needle secured adjacent to the opposite end of said feeder plate, said knob being for manual movement set forth in claim 3 wherein said clutch includes a gear operatively connected to said drive means and having a gear face, an adjacent end of said cam adapted to coact with said gear face to form a mechanical clutch mechanism.

UNITED STATES PATENTS Adler Nov. 19, 1918 Pen-as Oct. 16, 1923 Schloss Nov. 20, 1945 Sutker Mar. 9, 1948 Ross et a1. --a Jan. 17, 1956 FOREIGN PATENTS Great Britain June 20, 1956 

